A new instrument and technique for diagnosing electromagnetic design problems in microwave module housings and component packages

With the aim of diagnosing electromagnetic (EM) design problems in microwave module housings and component packages, a method of measuring the frequencies at which resonances occur and the distribution of the associated electric field intensity at the inside face of the housing or package lid has been developed and tested. The method does not require modification of the connections to the microwave assembly within the housing. The housing or package only need have a flat lid and that it be left off so that the item under test can be mounted on an equivalent flat plate on the test instrument. The microwave assembly in the housing or package may be operated normally while resonant field distributions are being measured. The prototype instrument yields results that demonstrate the practical application of this measurement assembly as a diagnostic and design development tool for microwave housings and packages of rectangular metal box shape. Resonances in the 8-12-GHz range have been accurately measured and indicate that by scaling dimensions an assembly for use at millimeter wavelengths is feasible